1. Field of the Invention
A process for the production of N-acylimidazoles by the reaction of a carboxylic anhydride with a carbonyldiimidazole is disclosed. The products are useful as chemical intermediates.
2. Technical Background
H. A. Staab, Angew. Chem. Intl. Ed., vol. 1, pp. 351-367 (1962) describes various syntheses and uses for N-acylimidazoles (called therein "imidazolides"). At pp. 355-56 the reaction of carbonyldiimidazoles with carboxylic acids, to give one mole of N-acylimidazole, one mole of CO.sub.2 and one mole of imidazole per mole of starting material is described. No mention is made in this article of reacting carboxylic anhydrides with a carbonyl-diimidazole to form N-acylimidazoles.
It is the object of the present invention to provide a simple method for the preparation of N-acylimidazoles which gives only easily removable CO.sub.2 as a byproduct, and fully utilizes all of the imidazole groups in the carbonyldiimidazole (all of the imidazole groups become N-acylimidazole).